Long-term remission of recurrent thrombotic thrombocytopenic purpura (TTP) after Rituximab in children and young adults.

INTRODUCTION

Acquired thrombotic-thrombocytopenic purpura (TTP) is an autoimmune disorder characterized by autoantibodies directed against the von Willebrand metalloprotease. Depletion of B-cells can prevent synthesis of this antibody and presumably induce remission of the disease. In adults, Rituximab (RTX) was effective in relapsed or refractory acute idiopathic TTP.

PROCEDURE

We report the long-term follow-up of five children and two adolescents (age at diagnosis 6-19 years, median 15 years) who were treated with RTX for recurrent or refractory TTP. Some of the patients suffered from recurrent refractory TTP with long histories of previous unsuccessful treatments. One had TTP associated with pancreatitis.

RESULTS

Three patients have been in complete remission after one treatment course with RTX. Four relapsed after 1 to 5 years, respectively, and responded to additional courses of RTX. One of them is in long-term remission after a third course of RTX and splenectomy. Compared to literature reports with a median follow up of 1.4 years (3-46 month), follow-up of our patients after treatment with RTX was very long (2-12.7 years, median 7.7 years). RTX therapy could induce long-term remissions in children with refractory recurrent TTP. Median duration of remission was longer and relapses per patient-years less frequent in patients receiving RTX compared to patients not receiving it. Remissions were achieved in children within one week, much faster than in adults.

CONCLUSION

Because of the rapid induction of remissions, RTX may be suitable for first-line therapy in pediatric acquired antibody-mediated TTP.